Data Migration System and Data Migration Method

1. A data migration system, comprising: a first storage system coupled to a host system; a second storage system coupled to the first storage system and the host system; and a management terminal coupled to the first storage system, second storage system and the host system, wherein the first storage system comprises: a first upper level logical volume; a first lower level logical volume which is thin provisioned and configured from a plurality of virtual areas; a first pool which is a storage area configured from a plurality of first physical areas; and first thin provisioning information representing which first physical area is assigned to which virtual area of the first lower level logical volume, wherein, upon receiving a write request designating the first upper level logical volume, the first storage system assigns the first physical area from the first pool to a virtual area of a write destination in the first lower level logical volume of the first upper level logical volume, writes write target data in the assigned first physical area, and updates the first thin provisioning information, wherein the second storage system comprises: a second upper level logical volume; a second lower level logical volume which is external; a third upper level logical volume which configures a pair with the second upper level logical volume and which is a copy source; a third lower level logical volume which is thin provisioned; and a second pool which is a storage area configured from a plurality of second physical areas, wherein the management terminal is configured to issue a command to the second storage system so that the second storage system maps the first upper level logical volume to the second lower level logical volume, issue a command to the host system so that the host system switches an access path between the first upper level logical volume and the second upper level logical volume, issue a command to the second storage system so that the second storage system executes copy processing of migrating data from the first upper level logical volume to the second upper level logical volume and copying the data from the second upper level logical volume to the third lower level logical volume through the third upper level logical volume.

2. The data migration system according to claim 1 , wherein the second storage system further comprises a cache memory, and wherein the management terminal is configured to issue a command to the second storage system so that the second storage system inhibits the cache memory operation, send a data migration processing mode to the second storage system, receive display information representing required pool capacity and pool unused capacity from the second storage system, and display the display information.

3. The data migration system according to claim 2 , wherein the management terminal is configured to display information including at least one of the following (a) to (f), and (a) information showing whether the first upper level logical volume can be migrated to a specific storage hierarchy of the second storage system by showing the comparison of required second-pool capacity and second-pool unused capacity of respective hierarchies, (b) information showing whether migration target data which is data in the first upper level logical volume can be migrated if distributed to a plurality of hierarchies by comparing the required second-pool capacity and the total second-pool unused capacity of all hierarchies, (c) information illustrating a storage example upon distributing and storing the migration target data in a plurality of hierarchies, (d) information showing the comparison of the required second-pool capacity of the respective storage hierarchies and the unused second-pool capacity of the respective hierarchies, (e) information showing whether the migration target data can be stored by changing the hierarchy of its storage destination by showing the comparison of the total required second-pool capacity of all hierarchies and the total unused second-pool capacity of all hierarchies, and (f) information illustrating a specific example upon changing the hierarchy of the storage destination, wherein, when the second-pool unused capacity is not insufficient, the management terminal is configured to issue, to the second storage system, a command to allocate the second-pool unused capacity, when the second-pool unused capacity is equal to or less than a threshold in the second storage system, receive a message, from the second storage system receiving the command to allocate the second-pool unused capacity, representing the second-pool capacity needs to be expanded after the copy is complete, display the received message, and obtain an input of the final determination of whether to start the copy processing.

4. A management terminal, comprising: an interface device coupled to a first storage system, a second storage system and a host system; and a processor coupled to the interface device, wherein the first storage system coupled to the host system comprises: a first upper level logical volume; a first lower level logical volume which is thin provisioned and configured from a plurality of virtual areas; a first pool which is a storage area configured from a plurality of first physical areas; and first thin provisioning information representing which first physical area is assigned to which virtual area of the first lower level logical volume, wherein, upon receiving a write request designating the first upper level logical volume, the first storage system assigns the first physical area from the first pool to a virtual area of a write destination in the first lower level logical volume of the first upper level logical volume, writes write target data in the assigned first physical area, and updates the first thin provisioning information, wherein the second storage system coupled to the host system comprises: a second upper level logical volume; a second lower level logical volume which is external; a third upper level logical volume which configures a pair with the second upper level logical volume and which is a copy source; a third lower level logical volume which is thin provisioned; and a second pool which is a storage area configured from a plurality of second physical areas, wherein the processor is configured to issue a command to the second storage system so that the second storage system maps the first upper level logical volume to the second lower level logical volume, issue a command to a host system coupled to the first and second storage systems, so that the host system switches an access path between the first upper level logical volume and the second upper level logical volume, issue a command to the second storage system so that the second storage system executes copy processing of migrating data from the first upper level logical volume to the second upper level logical volume and copying the data from the second upper level logical volume to the third lower level logical volume through the third upper level logical volume.

5. The management terminal according to claim 4 , wherein the second storage system further comprises a cache memory, and wherein the processor is configured to issue a command to the second storage system so that the second storage system inhibits the cache memory operation, send a data migration processing mode to the second storage system, receive display information representing required pool capacity and pool unused capacity from the second storage system, and display the display information.

6. The management terminal according to claim 5 , wherein the processor is configured to display information including at least one of the following (a) to (f), and (a) information showing whether the first upper level logical volume can be migrated to a specific storage hierarchy of the second storage system by showing the comparison of required second-pool capacity and second-pool unused capacity of respective hierarchies, (b) information showing whether migration target data which is data in the first upper level logical volume can be migrated if distributed to a plurality of hierarchies by comparing the required second-pool capacity and the total second-pool unused capacity of all hierarchies, (c) information illustrating a storage example upon distributing and storing the migration target data in a plurality of hierarchies, (d) information showing the comparison of the required second-pool capacity of the respective storage hierarchies and the unused second-pool capacity of the respective hierarchies, (e) information showing whether the migration target data can be stored by changing the hierarchy of its storage destination by showing the comparison of the total required second-pool capacity of all hierarchies and the total unused second-pool capacity of all hierarchies, and (f) information illustrating a specific example upon changing the hierarchy of the storage destination, wherein, when the second-pool unused capacity is not insufficient, the processor is configured to issue, to the second storage system, a command to allocate the second-pool unused capacity, when the second-pool unused capacity is equal to or less than a threshold in the second storage system, receive a message, from the second storage system receiving the command to allocate the second-pool unused capacity, representing the second-pool capacity needs to be expanded after the copy is complete, display the received message, and obtain an input of the final determination of whether to start the copy processing.